[Note: A provisional full text PDF of this article is available at http://www.translational-medicine.com/content/pdf/1479-5876-10-191.pdf. This study by ME/CFS researchers at clinics in Canada and several US states measured a broad range of cytokines, using uniform laboratory protocols, in patients diagnosed according to uniform criteria, all after infection with the same pathogen (Epstein-Barr) and all still ill at 24 months post infection. Cytokines, produced by the immune system, are involved in the inflammatory response.]

Abstract:Background: As Chronic Fatigue Syndrome (CFS) has been known to follow Epstein-Bar virus (EBV) and other systemic infections, our objective was to describe differences in immune activation in:

• Post-infective CFS (PI-CFS) patients

• And recovered controls.

We studied 301 adolescents prospectively over 24 months following the diagnosis of monospot-positive infectious mononucleosis (IM).

We found an incidence of CFS at 6, 12 and 24 months of 13%, 7% and 4% respectively.

In constructing a linear classification model IL-6, 8 and 23 were selected by two different statistical approaches as discriminating features, with IL-1a, IL-2 and IFN-gamma also selected in one model or the other.

This supported an assignment accuracy of better than 80% at a confidence level of 0.95 into PI-CFS versus recovered controls.

Conclusion: These results suggest that co-expression patterns in as few as 5 cytokines associated with Th17 function may hold promise as a tool for the diagnosis of post-infectious CFS.